"In the Buddhist literature there are the Jatakas, three of which deal with the story of Rama... The most noteworthy of these is the one called Dasaratha Jataka... The carry-over of these Jataka stories to China only serves to emphasize how popular was the Rama story even with the Buddhists."
January 1, 1970
https://en.wikiquote.org/wiki/Historicity_of_the_Ramayana